FPCN39 CWLW 151459
SMOKE CONTROL FORECAST FOR COASTAL BC AND THE INTERIOR INCLUDING THE
NORTHEAST ISSUED BY THE MOUNTAIN WEATHER SERVICE OFFICE OF
ENVIRONMENT CANADA AT 8:00 AM PDT Friday 15 August 1997 FOR TODAY.

VENTILATION INDICES (TEMPERATURE) AND MIXING HEIGHTS.
MIXING HEIGHTS IN METRES ABOVE SEA LEVEL.
AVERAGE WINDS IN KNOTS.

SPOT INDICES ARE DETERMINED BY THE ASPECT AND ELEVATION OF THE SITES.
COMPARE WINDS, TEMPERATURES AND ELEVATION WITH THE SITES HERE
TO DETERMINE THE INDEX IN ANY OTHER AREA.

SOUTHERN INTERIOR

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
FRSR CANYN   KEL      12   21     500   1    100   27    1950  12
KAMLOOPS     KEL      12   23     600   1    100   27    3350  16
OKANAGAN     KEL      10   19     500   1    100   26    2400  14
CASTLEGAR    SPOK      9   19     500  10    100   25    1700  10
CRANBROOK    SPOK      9   17     950  25    100   23    1700  27
REVELSTOKE   KEL      10   19     500   1     40   23     900   4

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PENTICTON    N   11   N   22   N   28
CRANBROOK             NE  11   NE  30

           INVERSION HT    BREAKTHRU TEMP
KELOWNA          700 m         21 C
SPOKANE          nil           23 C

TODAY'S VENTING: Good except poor through eastern valleys.




VENTING FOR SATURDAY: Good




VENTING OUTLOOK SUNDAY THRU TUESDAY: Fair to good.




CENTRAL INTERIOR/NORTHEAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
WILLIAMS L   P.G.    100   17    2450  24    100   22    3950  27
PR. GEORGE   P.G.    100   17    1850  18    100   22    3700  23
SMITHERS     P.G.     47   16     950  10    100   20    2350  19
WELLS GRAY   P.G.    100   17    4000  27    100   21    4000  27
FT NLSN      F.N.    100   14    1150  28    100   20    2700  28
FT STJOHN    F.N.    100   13    1750  29    100   17    2700  28

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
PR. GEORGE            NE  30   NE  28
SMITHERS              NE  17   NE  28

           INVERSION HT    BREAKTHRU TEMP
PR. GEORGE       nil           12 C
FT. NELSON       800 m         12 C

TODAY'S VENTING: Good.




VENTING FOR SATURDAY: Good




VENTING OUTLOOK SUNDAY THRU TUESDAY: Fair to good.




COAST

           UPPER      ***** MORNING ******    ***** AFTERNOON ****
             AIR      VI  Tmp  MXG HT  Wnd    VI  Tmp  MXG HT  Wnd
                               (mASL)  (kt)            (mASL)  (kt)
VANCOUVER    QUIL     73   20     700  15     78   23     850  14
FRASER VLY   QUIL     64   20     700  12     76   26     950  11
SRN VRISL    QUIL     56   18     650  10     67   23     800  10
CNTRL VRISL  QUIL     61   22     750  10     76   28    1050  10
NRN VRISL    HRDY     50   16     450  12     88   20     850  16
TERRACE      ANT       9   19     200  12    100   26    2200  14
STEWART      ANT      35   19     250  12    100   26    1900  14

*SUBTRACT 20 FROM THE VENTILATION INDEX IN VALLEYS IF THE MIXING
HEIGHT IS BELOW THE HEIGHT OF THE LOCAL HILLS.

FORECAST UPPER WINDS FOR FRIDAY AFTERNOON (WINDS IN KM/H):
             900m     1800m    2700m
VANCOUVER    N   19   N   22   NE  26
PORT HARDY   N   31   N   28   N   31
SANDSPIT     N   33   N   20   N   24

           INVERSION HT    BREAKTHRU TEMP
QUILLAYUTE       795 m         26 C
PORT HARDY       900 m         23 C
ANNETTE          500 m         21 C

TODAY'S VENTING: Fair becoming good this afternoon.




VENTING FOR SATURDAY: Good.




VENTING OUTLOOK SUNDAY THRU TUESDAY: Fair to good.




VENTILATION GUIDELINES:
          0-33.....POOR
          34-54.....FAIR
          55-100.....GOOD.
VENTILATION INDICES NORMALLY DROP TO POOR AFTER SUNSET.

END/mwso